Thermo-electric generator.



J. J. COOK.

THERMO ELECTRIC GENERATOR.

APPLICATION FILED MAR. z5, 1911.

Patnted Deo. 30, 1913.

4 SHEETS-SHEET l,

J. J. COCK.

' THERMO ELECTRIC GENERATOR.

' APPLICATION FILED 111111151911. P t t 1D 1,083,191. a en e1 110.30, 1915.

L SHEETS-SHEET 2.

J. J. COOK.

THERMO ELECTRIC GENERATOR.

APPLICATION FILED 111111.25, 1911.

Patented Dec. 30, 1913.

4 SHEETS-SHEET 3.

J. J. COOK.

THERMO vELEGTRIG GENERATOR.

APPLIOATION FILED 111111.25, 1911.

Patented Dec. 30, 1913.

4 SHEETS-SHEET 4.

attoznm I -To allwzom it. may concern inrrnn srarns rn JAMES J. Coon, or JERSEY curr, vNEW JEnsnY.

Be it known that I, J AMES J Coon, a citi- Vzen of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented a new and |useful Thermo-Electric` Generator, of which the following is a specification.

This invention has reference to improve' and being so constructed that its life is markedly prolonged.-

In accordance with the 4present invention the thermo electric pile is madeup of like elements, formed of materials well separated in the thermo electric order, joined in-cou ples and the 'couples rouped into piles of any desired number og groups.

' .The separate elements as to form and size may be all alike and are so constructed as to provide large contact surfaces between the elements of each pair and the contact surfaces are brought into engagement by `suii ciently heavy pressureto provide very-low internal resistance because of such large surface and intimate contact, the union of the elements 'of dissimilar materials into pairs being brought about without the use of'xany cementi'ng material,V so that the junction is solely by contact. Moreover, the joined terminals of the piles of pairs of elements are so disposed andthese elements are so formed that the ends of, each element are suiiiciently separated but still electrically connected, and' there is produced through the ends of the pile channels for the passage of heating andA cooling mediums, the passages being shaped to-present a large surface to the action of suchmediums.

`The two ends of the` pile where traversed by the passages are made alike so that either end is adapted to be traversed by a heating =1nedium and eitherend isY adapted to be traversed Vby a cooling medium, whereby a suitable heatingfmedjum'ma be-caused to flowl through the passagej orme'd bythe union of suitably-pierced end members or terminals of the .elements when joined vinto .Specification of Letters Patent.

THERMO-ELECTRIC GENERATOR ratentednee. so, i913.

- Application led March 2,5, 1911. Serial No. 616,825.

a pile at one end of said plie, ano a cooling medium may be caused to flow through the hke passage similarly formed at the other end of the pile, these passages being interior tothe vrespective ends ofthe pile .and the heating and cooling mediums being brought the elements are formed.

After a thermo electric pile has been used y into direct contact with the metals of which for some considerable time it is found that the joints deteriorate so that the output of the pile is diminished and ultimately such a pile will deteriorate to such an extent as to render it practically useless.

lVith the thermo electric pile of the present invention such deteriorating action readily counteracted by a reversal of the `application of the heating and cooling-mediums, so that the heating medium is made .to traverse the end of the pile previously` subjected to the cooling medium and the cooling medium is made to traverse the end of the pile previously subjected to the action of the heating medium, the external electrical connections being properly adjusted in accord-V ance Awiththe change. Because of'this reversal the pile is restored to its original` working condition and so remains until deterioration takes place in the joints in the reverse action of the pile,"when the defect` may be again remedied by restoring the re lation of flow of the heating and cooling mediums as at rst, and such reversal may be brought about from time to time as necessary, thus rendering the life of the pile almost limitless.

' Ifhi invention will be best understood from a vconsideration of the following de-v tailed description taken in connectionwith the accompanying drawings forming a part of this specification, with the understanding,

however, that while the drawings show a commercial form of the invention such showing Ais only some of -many forms which the invention may assume, and consequently the invention vis not. limited to the exact showing of the drawings, but 'may be varied within`V -wide limits without departing the salient features of the invention.

'In the drawings z-Figure 1 is a iper-speofv elements.

Fig. 4L is a section on the line 4-4 of Fig. 3. Fig. 5 is a plan view of one of the' elements of the pile. Fig. 6 is a plan view of an insulating washer used to separate the connected ends of each pair of elements from the like connected ends of adjacent pairs of Fig. 7 is a plan view of an insulating anchor member employed in elongated piles. some parts in section of a modied form of the invention. Fig. 9 is a plan view of the structure shown in Fig. 8 with parts in section on the linel 9 9 of Fig. 8. Fig. l0 is a.

plan view of a thermo electric element used in the pileof Figs. 8 and 9. Fig. 11 is a planview of an insulating washer used in connection with the element of 10. Fig. 1,2 is a plan view with one end in section of a modified form of element differing from that of Figs. 5 and 10. Fig. -13 is a section. on the line 13H13 of Fig. 12. Fig. 14- isa plan. View of aterminal connector used in connection with the pile. Fig. 15 is a plan View of an intermediate connector for electrically coupling two adj acent groups of elements. Fig. 16 isa section'similar to Fig. 3, with parts in elevation, of a Structure wherein but a Single group vof 'elements constitutes a pile." Fig. 17 is a plan view of an element which may be used in connection with the structure Iof Fig. 16. Fig. 18 is a plan view of one of the heads used in the construction shown in Fig. 16.'

Referringto the drawings, and first to the structure ofFigs. 1 to 6, there are AShown two heads 1, 2, which'm'ay be simple metallic blocks of rectangular or other form, each with one face substantiallyv plane and the other face, which in the-assembled generator constitutes the outer face of the block, provided with a centralized boss 3, `each boss 3 and the respective head block 1 and 2 being provided with passages leading from the outer face of the boss to the inner face of the block, and these passages are traverscd by bolts 4, 5, respectively, it being understood that usually two bolts are suili-` cient in the smaller types of thermo electric generators, whilemore bolts are needed in the larger types. These bolts may be em- ,ployed as terminals for the-generator and since -for strength and l,rigidity the heads 1 and 2 are ordinarily madeof metal, the bolts are insulated from the respective heads by insulating sleeves (S, 7,'f respectively, each bolt being insulated from one head by .a sleeve 6 and 'from the other head by a sleeve 7 and the latter is vmade sulliciently long to not only extend through #l-e corresponding head but toy extend" sub sutially .the 'full length of the bolt toward lgie other head, the

sleeve 7 terminating at an enlargement 8 formed on or secured tcthofbolt near the inner face of the' corresponding head for apurposc which will.- hereinafter appear.

Fig. 8 is an elevation with` Each bolt has applied thereto at each end a nut 9 between which and the adjacent boss 3 there is interposed a washer 10 of insulating material, and, if desirable, a washer 11 of metal or other'suitable.resisting material, while at one end each bolt has applied thereto an additional nut 12 and washer 13 whereby the nut 12 in conjunction Withthe washer 13 and the nut 9 may be utilized as a'binding post or connecting means for an external conductor indicated at 14 in Fig. 4. The bosses 3 serve tostiifen the heads 1 and 2 and the bolts l.land 5 serve as clamping means for forcing the heads one toward the otherto engage intermediate members and hold .themtogether with anydegree of pressure which the bolts will permit.

yThethermo electric pile is composedv of elements 15, 16, respectively, one of which,

say the element 15, is shown separately in Fig. 5, and as the contour of both elements is the same a description of the element 15 ,as shown in Fig. 5 will answer as well for the' element 16, the only difference between the two elements being that one is made of Aa metal Aor alloy at or near oneend ofthe thermo electric series and the other is made of another metal or alloy at or near the other en'd of the thermo electric series. The two` metals usually employed are antimony and "bismuth, but the present invention lis by no means limited to these two metals, since other metals or alloys may be employed, the' junction strip 17 and terminal heads 0r enlargements 18, the latter beingcircular, as

indicated in the drawings or any other appropriate shape, the circularshape being generally preferred. Each element may be of the same thickness throughout, or th*l central web may be thinner than the tei-initial portions or heads as will hereinafter appear 'lio with reference to Figs. 12 and 13, but in each 'f instance the-heads are of relatively large diameter and flat and of the same thickness throughout from the midline of the element to both faces of the head. .y

rated, as indicated at 20, although the par;

`ti,cular`for1nation of the walls is not material to the present invention, except that it is desirable that the walls of the passage 19 periphery of the head 18.` The web 17 should be as great or greaterin width than the distance betweenthe Walls of the passage 19 and the outer periphery of the head 18, so that the web 17 will add practically nothing to the resistance of the element.

rlhe ositive and negative elements have the heat s 18 in actual contact at one-end and the heads 18 at the other end in actual contact with the like heads of the next adjacent elements, while the heads 18 of a pair of elements remote from those in actual contact areyscparated by a Washer 21 of insulating material, preferably of a refractory nature, and one unalected by liquids or the vapors of liquids, mica being preferred because of its insulating, refractory and inert nature. Mica is. also to be preferred because it may he obtained and used in very thin lamina and will withstand great pressure, thel structure s `of thepresent invention, as will hereinafter appear, providingffonthe vexercise of great pressure upon the thermo electric elements andi the dierence o otential being comarge ele :tro-motive force is to be generali the insulating-washers2lmay be made rell atively thicker, but thcse'are structural details which need. not li particulari'zed. It Y :is to be observed thateach element and '1G- is identicaly one with the otherexcept as ,to thematerial used and that the two heads 18 of each element arealike. 'A

-Whenthe elements 15. and 16 are assembled -in a pile, the webs 17 are slightly. bent,

.Ysince at one end a pair of positive and negative elements have the broad faces of the y respective heads 18 parallel and in actual contact, while at the. other end the heads 18,

mare separated by a washer 21 though still` heads 18 ofathe elements 15 and 16 in actual contact are forced together most intimately,

whereby a better union is obtained than can be obtained by the use of a metallic cement and most excellent-electrical contact equal.

feet electrically aste-'present no noticeable` resist-ance wherebyinternal resistance of the are employed 1s sofsmall as to ,permit the generation of a large current, it being commercially 4practicable to obtain. from two' hundred to three hundred pairs of elements,

the number varying in accordance with'the aratively,` small, f re. comparativi?.

pile even wherealar'ge number of elements;

difference in temperature of the heating and chilling mediums, a current approaching fifty amperes in -volume at a pressure of about one volt, the separate elements in such a plle having the heads 1S about one and a of the element being about four inches, while the thickness of each element may approximate one-eighth of an inch. The foregoing figures are t0 be deemed as only approximate, but are based upon results obtained from practical workingstructures made in accordance with the present invention.

In ,the structure shown in Figs. l, 2, 3 and 4 there are three separate groups of pairs of elements united electrically into a single pile, and these groups are so placed. that the Webs 17 of one group are in parallel spaced relation to the Webs 17 of the other groups,

while the bolts 4 and 5' extend through the spaces between the outside groups and the central group and these bolts serye to firmly clamp the several groups with the contact- .ng faces of the heads 1S engaging each plantsif, for instance, it be desirable that each pile should generate an electro-motix-'e force of one volt and that the heating and cooling elements employed could be obtained -with a certain temperature difference, then two or three hundred pairs of elements will be assembled in two, three or moregroups between appropriately shaped heads 1 and 2, s'o that at the terminals of the pile with the heating and cooling fluids available there half inches in diameter and the total length Will be produced a difference of potential x of one volt. 'The elements are so assembled that all those of a group have the passages 19 through the heads 1S on the corresponding ends of the elements in alinement and there is thereby produced a passage thiough cach side of each group of joined cleunnts which group is firmly held in position by the clamping action of the heads 1 and 2 engagilo ing the opposite ends of the group and -forced into firm Contact therewith by the bolts et and 5'and their nuts 9. The opposite ends lof theipassages through each group are made to matchpassages 21a, 22 through respectivef heads -1 and 2, the passages 21LL being enteredfrom the ou'ter face of the.

head 1 by pipes 23 which on one side of the head 1 are united into arsingle pipe 24 and those on the iother sidero-f the head 1 are of the head 2 are united intoarsingle, pipe-,27

united into a single pipe'25. The passages 22 are entered by pipes 26 which onvone side,

and. on the other side of the head2 into a single pipe 28, and the pipes 27 and 28 each contain i valve 29.

When each group of elements contains a i, sufficient number of elements to considerably elongate the group,vthere is a possibility of lthe outside groups buckling, and to prevent this certain of the'washers 21 may be replaced by an elongated strip 30 of mica i or other suitable insulating material pro vided with passages 31 like the central pas- Sage through each-washer 21, both of these passages 31 and the passage through each washer 21' being of a size equal to the diam# eter of the passage 19 through eachl head 18 to the extreme ends of the notclies'forining the serrations 2O. A By providing an appropriate'number of strips 30 the tendency of the groiips of elements to buckle in either direction is overcome.

It is usually desirable `that each pileshould be a unit of manageable size, al-

- though this does not preclude the construcx cable.

other passage 84 therethrough designed to be traversed by the bolt ft or 5 as the case may be, in contact With the `enlargement 8,

thereof, an isolating washer being in terposed between the connector 32 and the head 1 or 2 as the case `may be. i

The groups of elements are united at the proper ends by other connectors 3U which inv general shape may agree to the. forni of an element- 15er 1G, having at each end a liead with :rpaSsageiBS therethrough like the passage 3 1 in the strip v30 or the pas-,

.sages through "the, Washers 21and these heads are` unltcd by a connecting web 39, which, however, inay bey shorter than` the 1 connecting webs I7 because the groups of elements inay be in closer relation than are the ends of the individual elements.

The electric circuit is readily traced from Fig. 4 where the lead 14 may be considered as connected tothe bolt 4, and this bolt is in electrical connection with the corresponding end of one ofthe end groups of el-enieiitsby af coniiector33 shown in dotted lines in Fig. L The circuit may then be traced hack and forth to thel'elenwiits of the group from ciid to end of theY several elements until the last element at the end rienio'te from the connect'or 33 is in electrical contact vWith a connector 3G, which extends tothe correspond .ing end of the intermediate group, whence .throu gh the intermediate grou tive ofthe demand lfor current upon the the circuit may be traced back and forth to the other end thereof, which is the en adjacent to the connector 33, and this end of the group is coupled by another connector 36 'shown in Fig. 4 in dotted lines to the corresponding end of the other end group, whence the circuit may be traced through this last named group to the'end thereof remote from the connector 36-Where there is applied another connector 33 leading to the bolt 5 and to' this bolt 5 the other lead 14 is connected.v It

will thus be seen that the several elements of the pile, although in the particular showing of the gure they4 are assembled in three groups, are all connectedin series andthe voltage of the' pile is that of the snm of the potentialdifferences of all the separate pairs or couples of elements and the-ciirrent'which may be drawn fromv such a piley YYil'lldependupon 'the internal"resistance"avhich, as-be' fore stated, is very l iW.-'l 5' "Jf' Let it be assumed`that`tliepipe7241 'is-in communication with a source 'of cooling l 2a is in coniniunication with asource of medium, such as ivater, 'and `thafjf-thepipe heating medium, suchas steam. fThe-Water may be ice water,- or `water at atmospheric temperature. The steam i'iiayfbe's-tea-m Iat but a few degrees above the temperature `of" boiling Water,=or it may be .ls'upei'heated 5, steam at high temperature and pressure,- all these conditions `modifying the/electrical outputof the .pilelf The' valves 29 will. con; 2 -ioez inediun'i through the elementaandit will be trol the tloiv lof -tlie heating and rcooling observed that these mediums both` come in direct contact with the Walls of the passages 19, and.v since these walls. are serrated or similarly formed they present comparatively large conducting. surfaces to be affected by the mediumstraversing the conduitsformed by thealined passages-l9..

The result of' the heating and cooling mediums is to highly heat one endrof each group of elements and to chill the other end of such group, anditliere is, therefore, es-

tablished a ina-rked temperature ,difference betweeiithe tivo* ends of thegroups with Ithe, resultant production of an electric current.

g mediun'is the tempera;

heating4 and, coo

iy `be maintained irrespec-j.

ture difference i pile, the greater' the. demand Witlrinfthe.Y

By properly controlling the lOW oftheQ-j capacity vof thepile reqiiiring'a greater ab;l sorption of energy vfrom the heatingand `cooling mediums. ,Y Where theV difference off". i

potential obtained is comparativelyI the non-conductive properties of ordinary water or of condensed steam areA suflicient to prevent any Amaterial lossof electric energy, because ofthe short cireuiting,of the elements bysuchl Water, but Where 'the difference of potential is suilleiently high or g dium is Wanted at less than atmospheric temperature the oil may be chilled.

It .ish-'noty mandatory thatthe bolts 4 and 5 extend 'through the spaces between the groups of elements, :tor instead or" theA structure of Figs. l to 5, the structure of Figs. 8 to 1l may be employed.' In this form the head blocks typied by the block -1a are formed Where 'engaged by the thermo electric elements with a circular series of,passages 40 and Wlth another passage 4lce'ntral to each circular series of passages, the

passage 4l being traversed by an insulating sleeve 42 through which extends a bolt 43 havingthe end threaded, and to this end there is applied a nut 44, the ,nut lengaging a Washer 45, which in 'turn is insulated from the block 1a by an insulating Washer 46. Surrounding each series of passages 40 is a circular flange 47 extending beyond the'corresponding end of the bolt 43, and `to this flange is applied a cap 48 having a centrally located reducing nipple 49 into which is screwed a pipe 50 coupled to a pipe 51, Which may perform the same ofl'ice as the pipe 24 of Fig. 1. The other ends of the particular group of elements `shown in Fig. 8 are coupledrtvogether by a bolt 43a surrounded by au insulating sleeve .41a and in other respects .tli'e structure is the same as described vwith reference to the. first named ends of the elements, the block 1a being formed with a flange 47a like the flange 47 toswhich is applied a cap 48 carrying a centralized nipple 49a into which is screwed a pipe 50a connected to another pipe 51a. l

The thermo electric elements of the stl-no-l ture shown in Figs. 8 and 9 are identical one w ith the other, except as to the material em- ,ploycd in their construction and diller from the thermo electric elements of Fig. 1 in that these elements indicated* at 52 and 53,. re-

spectively, in` Fig. 8,' and one of which, the

element 52, is shown in Fig. 10, have ternlinal heads 54 joined by a connecting Web, and each head 54 is formed Witlra circular series ol' passages 5G matching the passages 40 in the'clagrrping head l, Each head 54 is provided with a centralized passage 57 for the insulating sleeve 42. thermo electric elements to be insulated one from the other are separated by Washers 58,

v nach of which is formed with a central passage 5f) and a circular series of other passages 60 lin surrounding relation to the ceniral passage 59, these passages 60 matching the passages 56 in the heads 54. The structure of Figs'. 8 and 9 further differs from Y that o-Figjl inutilizing the terminal ele@ Gti ments 52 or 53, as the case may be, as termina-ls of the pile by providing such yele- 1 at a time as may be desirable.'

The ends of theA nels in each side of each group of associated thermo-electric elements. Otherwise the structure of Figs. 8 and 9 operates in the manner set forth With reference to the structure of Fig. l.Y

Since some of the metals Which are available for thermo electric elements are-cost-l it maybe found in large installations a visable to use as little of these costly metals as.` is possible Without materially aiecting the efficiency of the structure. In Figs.v 12 and 13 there is shown a thermo electric element wherein there is provided a Web 625L of a comparatively cheap material of good electrical conducting roperties, such, for instance, as copper, andJ this Web has at each endan annular head 63 of smaller external diameter than the diameter of the headof the thermo electric element and having a central opening 64 of greater diameter than the greatest diameter of the central passage through the head of the thermo electric element, even when the latter is serrated or otherwise suitably formed. Around the copper core so provided there is cast a head (35 completely embedding the annulus 63, so that the b road surfaces of each head present a large surface oithe particular metal de sii-ed for the thermo' electric element and more particularly Where suchmetal is of a costly nature. Where the metal is cheap this cost reducing expedientneed not be followed. The high electric conductivity of copper makes it possible to eep down the internal `resistance of the t errno electric elelnent and at the same time provide by the enveloping head 65 a terminal metal,- for the element of the desired thermo electric order.

.While the size of each pile or thermo elet'.` tric unit is not limitedA to any particular number or grouping of elements or pairs of elements, it is customary to form a. unit apable of a predetermined or standard voltage output, so that any desired voltage may be obtained inr a proper grouping of such units, Whichbecause of their similarity in action to electro-chemical batteries may be termed cells, and, therefore, to obtain any desiredcurrent to satisfy certain existing conditions a proper number of cells may be grouped in the same manner asv electrochemical cells are grouped, and the pipes conveying the heating and cooling mediums mayV be suitably grouped to supply all the cells simultaneously, or so many or" the cells iso' After continued use fora considerable period of time there is a liability of deterioration at the joints between the elements ofthe couples and with thermo electric piles as heretofore constructed the4 output was reduced until the pile asa whole `became useless.

IVith the present invention the source of heating and cooling mediums may be disconnected from the conduits leading into the cells and changed so that the heating medium may be caused to flow thro-ugh that.

. tion of the heatin'g and cooling medium l made with the greatest facility and thereto from time to time at such intervals as may be necessary the life of the cell may be prolonged almost indefinitely.

Since there is no positive union between 'the positive and negative elements making Aup the couples or pairs of elements of the cell or pile, the whole struct-ure is readily dismantled at any time on the removal of the clamping bolts so that repairs may be no skilled laboris needed for the making of such repairs. .y

The efciency of the thermo pile is materially enhanced by directing the heating and cooling fluids through channels within the ends of the groups or stacks of elements, since these liuids become active to the interior of the elements, it being found that the heating or chilling, as the case maybe, is more effective when it is applied interiorly to the velements and exteriorly thereto.

Because of the great pressureused to force the meet-ing surfaces of the elements into contact one with the other, they may be made smooth on their contacting faces and still be so'I luid tight. However, this does not preclude the formation of these surfaces in other ways, whereby the electrical contact may be made extensive to correspondingly reduce the internal resistance of thepile, and the joints be made fluid tight.

Where it is desirable that the pile be composed of but a single group of elements, the structure-of Figs. 16, 17 and 18 may be employed. In this case heads 1b and 2b each proyided Witha boss 3a` disposed longitudinaliy of the head are used, and these heads may be longer than wide and may conform qulte .closely tothe shape ofthe elements whichiin Figs. 16 .and 17 are indicated at 15 and 16 and one element, say the element 15a, is shown separately in Fig. 17. In this structure the element 15a is an elongated element with rounded ends and with the portion between the ends of substantially the same diameter throughout, which diameter may be th'e same as the diameter ofthe rounded ends, although this particular shape is not mandatory, it only being necessary that the connection between the ends be of sufficient carrying capacity` to maintain' the low internal resistance of the pile. The elements'la and 16a are alike except as to the material used, and any suitable thermo electric materials may be employed as already described with relation to the other-figures. Each element, of `which the element 15a' of Fig. 17 may be taken as typical, is provided with a central perforation 19a in line with the end passages 19, which are like the passages 19 of the element 15 shown invFig. 5, although any other form of passage may be used. The heads lb and 2b are provided with passages 21a to match the conduits formed by the alined passages 19 and the passages through the Washers 21 which are employed in the structure of Fig. 16 in the same manner as described with reference to the other structures and pipes 23 lead into the passages 21a as in theL other forms and for the same purpose. `Each head 1b and 2*? is formed with a central passage 66 matching single bolt 68 need be used and the pile com- Y prises but a single grou'p of elements. The

operation of this st-ructure is the same as de scribed with reference to the other figures v and the structure is susceptible of various modifications in manyof its details. The pile or cell constructed in general accordance -With the arrangement of Fig. 16 is particularly useful Where a large output for each cell is not required and the cells may be' grouped in various Ways, so that any desir`v able output of a plurality ofcells may be obtained, depending upon the size of the individual cells, the number 'of' cells employed, the electrical connections of the cellsand the temperature dill'erence-between the ends of the elements, and this is alsov true of the. other forms shown and described.,

What is claimedis:'cv

-1, Anelemnt -for a theme-pile with terminal portions alike and each' having a passage therethrough for a temperature controlling medium'fsaid terminals each betact and provided with matching passages therethrough, and lthe couple being composed of materia-ls differing in the thermoelectric order.

3. An elementtor a thermo-pile ot the same thickness throughout and comprising laterally expanded terminal portions and an intermediate connecting web of less Width than the terminal portions, said terminal portions being provided with passages therethrough for a temperature controlling medium.

4. A thermo-pile comprising a group ot' elements each of equal thickness throughout and each having laterally expanded terminal portions with passages therethrough 'and constituting heads of the same thickness as the remainder of the element, said" elements being assembled with the heads face to face and in contact at alternate ends in series throughout the group with the heads all in planes parallel one to the other, the passages` through the heads where in contact forming conduits through the ends of the group for the low ot a temper- -ature controlling medium therethrough, and

terminal clamping members and connecting mea-ns therein holding the contacting ends of the elements of the group in tirm electrical and fluid tight engagement, said connecting means being out of the path ot action 'of the temperature controlling medium upon the thermopile elements.

5. A thermo-pile comprising a group of elements each of equal thickness throughout comprising terminal portions or heads and a connecting web", the elements having their terminal portionsin alternate engagement in series throughout the group and each in a plane parallel with the planes of the other terminal portions and the connecting webs being bent to correspond. to the displacement of the terminal portions, and said terminal portions having matching passages,

and positively acting clamping means engagingthe Aopposite ends of the grpup and holding the terminal'portions of -the elements in electrical and ilnid tight relation solely by the` pressure exerted by the clamping means. Y

6. A thermo-pile provided with elements each of equal thickness throughout with the Asolely by pressure.`

terminal portions in' alternate engagenient.`

and the intermediate portions bent to locate A the terminalportions in different parallell planes, and positively acting clamping means for holding the thermo-electric eletight contact ments in electric arid fluid 7. A thermo-pile provided with a group..

of elements constructed for the flow of a? heating medi im `therethrough each otequal thickness throughout with the terminal pori tions in alternateengageinentand the 'intermediate portionslphent to locate the terminal portions in diterent parallel planes-and positively acting clamping means for holding the thermo-electric elements in electric and fluid tight contact solely by pressure?,-

said clamping means extending through the thermo-pile interior thereto and out of the path of action of a heating medium on said.

elements. i 8. A'thermo-pile comprising a group ot.

thermo-electric elements in 'engagement at alternate ends throughout thepile'with interposed insulation at thez ends not in en. f I

gagement and the contacting v'ends of the throughout with the ehds iii diilerent paralv group of elements and interposed insula/tion lel planes andthe intermediate portions bent: p

to correspond thereto, clamping heads at the ends of the thermo-pile, and clamping bolts between the heads acting through the latter on the group of elements to hold said elements in electrical and fluidl tight Contact solely by the pressure exerted by the bolts 9. A thermo-pile comprising .a group of elements each ot' substantially even thickness throughout and having terminal portions formed with passages therethrough, and united by an electro conducting member, the thermo electric elements being assembled in a group with alternate ends in face conta-ct and the other ends separated by interposed insulation having passages matching the passages in the ends of the thermo electric elementenk all the. passages at the same end of the elements uniting to constitute a conduit-Q through the group., clamping heads forfftliiert group vof thermo electric elements 'engaging the ends of the groups and providedwith passages communicating directly Withtlie u conduits through thegroups, bolts extend; ing from head to head out of the path of. action of a temperature controlling medium i when flowing through a. passageL in the group of elements, said bolts exerting pres' pair consisting'of elements differing in the thermo electric order and each element of each pair being of substantially even thickness throughout and provided with laterally extended end portions and a connecting Web, they end portions being traversed by passages, each pair'of elements constituting a couple having the extended portions at one endzin :face contact and at the other end separated with interposed insulation also having passages therethrough alining with the passages through the corresponding ends lof the elements to form conduits through the group at opposite sides thereof, clamp heads applied `to the ends of the group and provided With passages communicating With the conduits through the group, means for directing temperature controlling fluids through the heads and by them to and through the conduits traversing the groups, and bolts for forcing the heads one toward the other to hold the thermo electric elements in good electric contact and in iuid v tight relation at the passages therethrough said bolts being located out of the path oi action of temperature controlling fluids traversing the conduits.

.11. A thermo-pile comprising groups of thermo-electric elements each of substantially equal thickness throughout and comprising a central web and laterally extended terminal vportions, or ends having passages therethrough, the extended portions at the alternate ends of the elements of each group being brought into parallel face to face contact and parallel to the planes of the ends of the other elements throughout the group, and the remaining terminal portions of the group of elements being separated by insulation, and means for holding the contacting faces and separating insulation at th ends of the elements in firm electrical and fluid tight relation.

In testimony, that I claim the foregoing as my own, I have hereto alfixed my signature in the presence of tWo Witnesses.

JAMES J. COOK.

AWitnesses:

JOHN H. SIGGERS, DAVID R. WAGNER. 

